Pencil sharpener



FIG. 1 is a right side elevational view of a pencil sharpener showing my new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view;

FIG. 5 is a rear elevational view; and

FIG. 6 is a front elevational view. 

The ornamental design for a pencil sharpener, substantially as shown. 